Geosynthetic Clay Liners in Alkaline Environments

Geosynthetic Clay Liners in Alkaline Environments PDF Author: JA. McKelvey
Publisher:
ISBN:
Category : Cation exchange
Languages : en
Pages : 11

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Book Description
The use of geosynthetic clay liners (GCLs) as secondary barrier layers in environmental applications such as landfills and other impoundment facilities is becoming increasingly more popular among the engineering community, particularly at project sites where earthen materials suitable for barrier layers may not be locally available. Design engineers for these environmental applications are becoming well versed at performing equivalency calculations comparing the performance of geosynthetic materials to their earthen counterparts. For barrier layers, these equivalency calculations would normally compare the mechanical and hydraulic properties of the GCL to a compacted clay liner. Of these properties, the ability of the hydraulic properties to withstand degradation due to permeation of contained leachates is of prominent concern. Such is the case in alkaline environments. The leachate may adversely affect the GCL by minimizing swelling, decreasing adsorption capacity and increasing the permeability of the material. If the effect on the material is significant, the usefulness of this product is diminished, possibly voiding any equivalency comparison to compacted clay liner performance. The design engineer must fully understand what effect, if any, specific leachates will have on the GCL being considered. Accordingly, appropriate performance testing with the leachate in question must be performed during the design phase and confirmed during construction through quality assurance testing.

Geosynthetic Clay Liners in Alkaline Environments

Geosynthetic Clay Liners in Alkaline Environments PDF Author: JA. McKelvey
Publisher:
ISBN:
Category : Cation exchange
Languages : en
Pages : 11

Get Book Here

Book Description
The use of geosynthetic clay liners (GCLs) as secondary barrier layers in environmental applications such as landfills and other impoundment facilities is becoming increasingly more popular among the engineering community, particularly at project sites where earthen materials suitable for barrier layers may not be locally available. Design engineers for these environmental applications are becoming well versed at performing equivalency calculations comparing the performance of geosynthetic materials to their earthen counterparts. For barrier layers, these equivalency calculations would normally compare the mechanical and hydraulic properties of the GCL to a compacted clay liner. Of these properties, the ability of the hydraulic properties to withstand degradation due to permeation of contained leachates is of prominent concern. Such is the case in alkaline environments. The leachate may adversely affect the GCL by minimizing swelling, decreasing adsorption capacity and increasing the permeability of the material. If the effect on the material is significant, the usefulness of this product is diminished, possibly voiding any equivalency comparison to compacted clay liner performance. The design engineer must fully understand what effect, if any, specific leachates will have on the GCL being considered. Accordingly, appropriate performance testing with the leachate in question must be performed during the design phase and confirmed during construction through quality assurance testing.

Testing and Acceptance Criteria for Geosynthetic Clay Liners

Testing and Acceptance Criteria for Geosynthetic Clay Liners PDF Author: Larry W. Well
Publisher: ASTM International
ISBN: 0803124716
Category : Geosynthetics
Languages : en
Pages : 270

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Book Description
An engineering perspective on the liners, which are used as barriers for containing liquid and in conjunction with geomembranes in landfills and capping systems. Explore aspects of testing for shear strength and long-term creep, issues and methods of testing for hydraulic conductivity, and specifica

Geosynthetic Clay Liners

Geosynthetic Clay Liners PDF Author: Erwin Gartung
Publisher: CRC Press
ISBN: 1000099857
Category : Art
Languages : en
Pages : 254

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Book Description
This text, based on an international symposium held in 1994, covers geosynthetic clay liners (GCL), a type of geosynthetic material which blends natural soil and geosynthetics in the form of a composite barrier-system. Environmental applications have been a major use of GCL.

Compatibility of Geosynthetic Clay Liners with Acidic Solutions

Compatibility of Geosynthetic Clay Liners with Acidic Solutions PDF Author: Yang Liu
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Geosynthetic clay liners (GCLs) are widely used as hydraulic barriers because of their sealing capacity in contact with water. However, with the increasing interest in their use in mining applications, the compatibility issues of GCLs to mining leachates are of some concern. This research work has been undertaken to enhance our understanding of compatibility of GCLs with strong acidic leachates, as for example, which may occur in mining leachates. Three types of bentonites were selected for this research program. Tests included index tests such as Atterberg limits, swell index, fluid loss and suspension rheology under various concentrations of sulfuric acid solutions. The results indicate that all index parameters degraded when the materials were exposed to acidic solutions. The degradation of these indices would indicate a high probability for the degradation of hydraulic performance of GCLs to occur based on established correlations between hydraulic conductivity and these indices. The mineralogical analyses on bentonite components of GCLs before and after reaction with sulfuric acid solutions were conducted using X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods. The dissolution of bentonite, loss of water from smectite interlayers, and the collapse of smectite layers were observed using these methods, these observations explained in part the degradation of the engineering indices and hydraulic performance of bentonites or GCLs. A series of flexible-wall permeameter tests were conducted to directly evaluate the hydraulic performance of GCLs when subjected to different concentrations of sulfuric acid solutions. Effective stress and prehydration condition, both of which can affect the hydraulic performance, were also considered. The hydraulic conductivity was observed to increase with increasing sulfuric acid concentration, but specimens prehydrated with water had lower resulting hydraulic conductivity to sulfuric acid leachates than non-prehydrated specimens. Higher applied effective stress tended to decrease the hydraulic conductivity presumably by compressing the specimens thereby resulting in smaller hydraulically active pores. Three powdered polymers, having either negative, positive or neutral charges, were used in this study to determine whether the hydraulic performance of bentonites under acidic conditions could be improved. Any improvements achieved were only observed under deionized water and low sulfuric acid concentration (≤0.015 M). Generally, no significant differences in test parameters caused by the polymer types (cationic, non-ionic and anionic) were observed under DI water and low sulfuric acid concentration (≤ 0.015 M). However, at higher acid concentrations, these polymers tended to lose effectiveness due probably to pH induced changes in polymer conformation, from presumably elongation to aggregate, at the clay surface. Sulfuric acid is detrimental to the hydraulic performance of GCLs, even if GCLs are prehydrated with good quality water. With better knowledge of how GCLs behave under strong acidic conditions, the geotechnical engineering community will be better equipped to approach and resolve potential problems involving interaction between GCLs and acidic solutions.

Advances in Geosynthetic Clay Liner Technology

Advances in Geosynthetic Clay Liner Technology PDF Author: Robert E. Mackey
Publisher: ASTM International
ISBN: 0803134843
Category : Clay
Languages : en
Pages : 161

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Book Description
Soon after the inception of ASTM D35.04 Subcommittee on Geosynthetic Clay Liners, the first symposium on Testing and Acceptance Criteria for Geosynthetic Clay Liners (GCLs), STP 1308, was held on 29 January 1996, in Atlanta, Georgia. The intention of the symposium was to bring together the current knowledge and understanding regarding this relatively new product used in containment systems. Since that symposium, numerous GCL standards have been developed along with a greater appreciation of the product's capabilities and limitations. ASTM D35 determined it was time to assess the current state of GCL technology to better address possible revisions of the present ASTM GCL standards and determine what new standards will be required in the future.

Field Performance of a Geosynthetic Clay Liner (GCL) Used as the Hydraulic Barrier Layer in a Landfill Cover in Southwestern Wisconsin

Field Performance of a Geosynthetic Clay Liner (GCL) Used as the Hydraulic Barrier Layer in a Landfill Cover in Southwestern Wisconsin PDF Author: Patricia Ann Thorstad
Publisher:
ISBN:
Category :
Languages : en
Pages : 280

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Book Description


Clay Geosynthetic Barriers

Clay Geosynthetic Barriers PDF Author: H. Zanzinger
Publisher: CRC Press
ISBN: 1000108066
Category : Technology & Engineering
Languages : en
Pages : 412

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Book Description
Clay geosynthetic barriers are most frequently used in environmental areas, such as landfill cover systems. This work discusses the durability and lifetime aspects of clay geosynthetic barriers related to the synthetic yarns and fibres.

Compatibility of Geosynthetic Clay Liners (GCLs) with Multi-species Inorganic Solutions

Compatibility of Geosynthetic Clay Liners (GCLs) with Multi-species Inorganic Solutions PDF Author: Dale Christian Kolstad
Publisher:
ISBN:
Category :
Languages : en
Pages : 374

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Book Description


5th ICEG Environmental Geotechnics

5th ICEG Environmental Geotechnics PDF Author: Hywel R. Thomas
Publisher: Thomas Telford Publishing
ISBN:
Category : Science
Languages : en
Pages : 852

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Book Description


Geosynthetic Clay Liners for Waste Containment Facilities

Geosynthetic Clay Liners for Waste Containment Facilities PDF Author: Abdelmalek Bouazza
Publisher: CRC Press
ISBN: 9780415467339
Category : Science
Languages : en
Pages : 0

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Book Description
Increasingly stringent regulation of pollution and waste production worldwide drives the need to isolate contaminants that pose a threat to human and environmental health by using engineered barrier systems involving the use of low permeable materials. Over the past two decades, geosynthetic clay liners have gained widespread acceptance for use in such barrier systems. They are often used as a component of primary and secondary base liners or final cover systems in municipal solid-waste landfills as well as in regulated industrial storage and mining waste-disposal facilities. This book gives a comprehensive and authoritative review of the current state of practice on geosynthetic clay liners in waste containments. It provides an insight into individual materials (bentonite and the associated geosynthetics) and the manufacturing processes. This is followed by the coverage of important topics such as hydraulic conductivity, chemical compatibility, contaminant transport, gas migration, shear strength and slope stability, and field performance.